Web printing paper and process for producing it

ABSTRACT

In a web printing paper the base paper comprises of more than 50% wt. de-inked recycled fibers, 10-35% wt. mineral filler and the remainder being wood-pulp and/or cellulose and has a weight of 30 to less than 60 g/m 2 . The base paper is coated with a coating having a weight of 2 to 8 g per m 2  and side and the binder proportion is no more than 15% wt. in relation to the coating pigment.

FIELD OF THE INVENTION

The present invention relates to a web printing paper, which has a basepaper containing mineral filler, recycled fibers and, as applicable,mechanical pulp and/or chemical pulp, and a coating on both sidescontaining pigment and binder. Furthermore, the invention relates to aprocess for producing the web printing paper.

BACKGROUND OF THE INVENTION

Basically, there are three main groups of press papers:

Newsprint

Super-calendared (SC) paper

Lightweight-coated (LWC) paper

The above-mentioned papers are used in the production of dailynewspapers, illustrated periodicals, magazines, catalogs and advertisingcirculars, such as those usually included with daily newspapers orillustrated periodicals.

In the past, there were many attempts to improve the quality of thesepapers while at the same time reducing production costs. This led toupgraded newsprint being used in areas which originally were reservedfor the higher-value SC papers; in turn, SC papers of improved qualitycould be used where only LWC papers had been used in the past.

An overview of the current press papers may be found in the "PaperManufacturing Weekly" (Wochenblatt fur Papierfabrikation) 9 (1988), pp.337-344. This study also describes a film press used to applypreparations to the paper types in question. SC papers and LWC papersare largely printed by the offset or gravure process, while newsprintsand upgraded newsprints are printed almost exclusively by the offsetprocess. Because the papers mentioned are supplied to the printingmachine exclusively in the form of webs, they are also referred tocollectively as "web printing papers." In this study, the fibercomposition of known European wood-containing offset papers is given as4 to 50% chemical pulp, remainder: mechanical pulp. The ash content ofnewsprints is given as 0 to 7%, and for SC papers 18 to 25%. The use ofrecycled fibers is not addressed.

The authors Bergh and Svenka report in the "Paper Manufacturing Weekly"16 (1990), pp. 701-708 and in "Pulp and Paper Canada" 92: 4 (1991), pp.52-58 on the surface treatment of newsprint with starch or pigmentationsin order to improve printability. Even a surface treatment carried outsolely with starch leads, at a applied coat of 1 g/m², to improvedsurface binding, resulting in a paper suitable for multicolor offsetprinting. The reduced whiteness, however, was disadvantageous. When,instead, a starch solution based on calcium carbonate or kaolin andpreparations containing 70% by weight starch ester, relative to thepigment, were applied with a so-called film press, a quality of improvedstrength and printability was created that could no longer be termednewsprint. Depending on the selected satinage conditions--super-calendar(SC) or soft-compact-calendar (SCC)--smoothness values between a maximumof <200 (SCC) and 1,000 Bekk/sec. (SC) were obtained. The base paperused for the starch/pigment application contained TMP (thermo-mechanicalpulp) as its main fiber components and an ash content of 0.4% weight.

The article: "The Production of High-Quality Upgraded Newsprint by anOn-Machine Surface Treatment with LAS (Liquid Application System),"Eucepa Conference Proceedings (1988), pp. 538-555 reports on the surfacetreatment of newsprint with starch, CMC or other film-formers and on theapplication of a lightly pigmented coating. The produced product is tosaid to fall between LWC and SC papers. The application of the surfacepreparation is, according to the article, carried out with the devicesknown as short-swell coaters or LAS. Better base papers, in respect tostrength, can be coated using the short-dwell system, while papers oflower strength can only be processed on an LAS device. If pigmentedpreparations are used, they have compositions of 50% coating kaolin and50% finely-ground calcium carbonate and contain binder shares of between50 and 200 parts by weight, relative to 100 parts by weight pigment. Iflatex is also used as a binder, its share of the total binder quantityis 10%. The prepared papers are subsequently treated on asuper-calendar. If only starch has been applied, a considerable increasein tensile strength as well as a lesser--and, depending on the appliedstarch quantity, lessening--increase in stiffness is observed. On theother hand, opacity increases considerably when the applied preparationconsists solely of starch. The application of pigmented preparations, inwhich the preparation having the lowest binder content consists of 33%by weight binder and 67% by weight pigment, also led to improvement incharacteristics, particularly in picking resistance, gloss and printinggloss, especially when the produced papers were also super-calendared;however, depending on the application device used, a considerabledeterioration in opacity occurred.

The composition of the base paper used, especially any share of recycledfibers present, the filler content and the grammage of the base paper,are not disclosed.

A further experiment to improve the quality of newsprint is described inthe Tappi Journal, November 1986, pp. 74-78. This report describes afiller added in the form of kaolin, up to an added quantity of 7% byweight, and the influence of various retention aids. The reported fibercomposition of sheets produced in laboratory attempts was 89% TMP and11% semi-bleached cellulose.

From the Japanese document laid open to public inspection No. 1174697, anewsprint is known, the fiber composition of which consists of 50% byweight mechanical pulp, 30% by weight recycled fibers and 20% by weightsulfate chemical pulp, and which has a coating of 3 to 8 g/m² and side.The coating pigments have an oil absorption capacity of at least 65 cm³/per 100 g. The coated paper has a whiteness of 61.8, while the basepaper has a whiteness value of only 50.7.

EP-0 377 983 A2 relates to a further development of the proposalaccording to the above-mentioned document; in addition, however, itcalls for an acicular pigment in the coating, which is to be applied bymeans of an air brush or a blade-coater. The coating weight to beapplied to an untreated paper containing 30% by weight recycled fibersis to be between 1 and 12 g/m², preferably between 3 and 8 g/m² and onthe printed side. All told, a grammage of 60 g/m² should not beexceeded. According to this document, the standard pigments can be usedas fillers for the untreated paper; their share is usually between 0.5and 10% by weight, preferably, however, it is even less than 0.5%. Forsatinage, a super-calendar and/or a machine smoothing unit is used.

The article "Surface-Treated SC Papers, a Challenge for LWC Papers"(Oberflachenbeschichtete SC-Papiere, eine Herausforderung fur LWCPapers), published in the "Paper Manufacturing Weekly" 1 (1988), pp. 1to 6, is concerned with the coating of highly-filled, wood-containingprinting papers for illustrateds. The coating formulations given in thisarticle for a paper to be printed by the offset process has abinder-pigment ratio of 0.5: 1 to 1:1. The high binder share isconsidered necessary in order to attain sufficient anchoring of thecoating and a corresponding increase in the strength of the base paper.In quality comparison to the known LWC papers, the surface-treated SCpapers have a lower whiteness, a higher opacity, and a clearly lowerpaper gloss. The ash content (filler content) of the surface-treated SCpapers described in this article is between 15 and 25% by weight. As theapplication device for the coating, an SDTA application system (shortdwell time) is indicated. The fiber composition of the untreated paperis not disclosed.

According to the recently published article: "Possibilities for theOn-line Coating of Filled, Wood-Containing Papers" (Moglichkeiten zumOn-Line Streichen von gefullten, bolzhaltigen Papieren) in the "PaperManufacturing Weekly" 13 (1992), pp. 507-515, highly-filled upgraded SCpapers are pretreated initially by means of a film press with apigmentation consisting of calcium carbonate and at least 30% by weightbinder, relative to the pigment, so that the papers have adequatestrength to be coated with the actual top coat in a second workstep bymeans of a blade-coater.

The top coats consist of mixtures of kaolin and fine calcium carbonate,whereby 12 parts by weight binder are used! in a 100 parts by weightpigment mixture. The minimum application quantity for the cover coat is7 g/m² and side; by way of example, reference is made to applicationweights up to a total of 19 g/m², while for the pre-coat 4 to 5 g/m² areindicated, so that at least 9 g/m² and side are applied. There is noinformation given on the fiber material of the base paper. Although theproduced papers, which represent a new type of coated paper quality,have some excellent characteristics, disadvantages continue to exist;the relatively high consumption of resources, in connection with thehigh costs of the base paper, the required double coat, and the highweight of the top coat, results in a paper which due to its productioncosts must remain excluded from significant areas of use.

The known proposals have led, in part, to new types of web printingpapers which have already made their way onto the market; however, thebasic disadvantage, namely, that the achieved improvements in qualityare accompanied by considerably higher production costs, continues toexist. For example, if an upgraded newsprint achieves the quality levelof a standard SC paper or if an upgraded SC paper approaches the qualitylevel of the known LWC papers, a simultaneous increase in costs to thelevel of the higher-valued type of paper could until now hardly beavoided, so that printers, as customers, had no great incentive toswitch over to the newly-developed types of paper. From theenvironmental point of view, there is the disadvantage that the use ofrecycled fibers is often still too low.

SUMMARY OF THE INVENTION

The object of the present invention is to provide web printing papershaving a satisfactory quality level, to increase the share of recycledfibers used and to permit web printing papers to be manufactured atfavorable production costs. In particular, the invention intends toprovide a web printing paper for gravure and offset printing, which isto be used in the areas previously reserved for the standard SC papers,while a further web printing paper for gravure and offset printing is tobe developed that can be used in the areas of the standard LWC papers.

In implementing the invention, the starting point was the realizationthat it is necessary, in order to maintain the desired spectrum ofcharacteristics, especially printability, to coat the surface of thepaper with a covering known as a coating or pigmentation, which containsbinder and mineral pigments. At the same time, however, economicconsiderations require that the costs for this coating be kept as low aspossible. Furthermore, it was recognized that in order to achieve asatisfactory cost/quality ratio, it would be necessary during theproduction of the paper to make use of an economical fiber material.

Starting from these considerations, a first embodiment of the inventioncalls for a web printing paper in which, on a base paper containingmineral filler, recycled fibers, mechanical pulp and/or chemical pulp, acoating containing pigment and binder is applied to both sides, wherebythe web printing paper is characterized by the fact that:

the base paper has a grammage of 30 to <60 g/m²

the base paper, relative to its grammage, contains:

>50% by weight de-inked recycled fibers

10 to 35% by weight mineral filler

remainder: mechanical pulp and/or chemical pulp and all weight parts addup to 100% by weight;

the coating is applied on each side in a quantity of 2 to 8 g/m² and thebinder, relative to pigment of the coating is present in a quantity ofnot more than 15% by weight. The production of the base paper inaccordance with the present invention is preferably carried out at a pHvalue of between 6.5 and 8.5.

In contrast to the above-described embodiment of the web printing paperaccording to the invention, it is foreseen according to a furtherembodiment that the fiber content of the base paper will consist solelyof de-inked recycled fibers. Filler content and coating, however, willcorrespond to the above-described embodiment.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Before discussing in greater detail the advantages of the presentinvention, its further advantageous embodiments and the process formanufacturing the web printing paper according to the invention, weshall explain the terms used in the Description and in the PatentClaims:

The web printing paper according to the invention refers exclusively tosingle-ply papers, in contrast to cardboard, for example.

Filler refers to the mineral pigments that are added to the fibersuspension during paper manufacture. No distinction is made here betweenfreshly added fillers and fillers which are added to the papermanufacturing process together with fiber material recovered from wastepaper. Recycled fibers are fiber material recovered from waste paper;according to the invention, especially those fibers are preferred whichare recovered from Waste Paper Category D31 on the list of Germanstandard types.

De-inked recycled fibers are fibers from which the printing ink has beenremoved to the greatest extent possible.

Mechanical pulp refers to wood fibers mechanically reduced in size,i.e., to both the so-called groundwoods and to the types obtained withthe help of refiners. A list of the various types of mechanical pulp isfound in "Cellulose and Paper" (Zellstoff and Papier) 37 (1988), p. 212.Of the types of mechanical pulp listed there, the so-called TMP material(thermo-mechanical pulp) is especially preferred according to theinvention.

Mechanical pulp and chemical pulp refer to "fresh" fibers, in contrastto recycled fibers based on mechanical pulp or chemical pulp.

The formulation, which is used in connection with the production of thebase paper, of a simultaneous two-side dewatering between two wires of apaper machine refers to manufacture on a wire part known as atwin-former on a paper machine.

The term film press is used here to identify all devices in whichpre-dosing of coating color is carried out by means of dosing rollers,blades and smooth or ridged rolling blades on a transfer roller, fromwhich the pre-dosed coating color is "indirectly" transferred to thebase paper web in order to form the coating. Further explanations arecontained in the reference materials discussed above: "PaperManufacturing Weekly" 13 (1992), pp. 507 to 515, as well as "PaperManufacturing Weekly" 6 (1992), pp. 193-197.

Hot-soft calendars are also known in the profession as soft-compactcalendars; the nips consist of a hot hard-cast roller and rollerscooperating therewith having resilient plastic; see also the "PaperManufacturing Weekly" 16 (1990), pp. 701-708.

All weights of fiber materials, base papers and coated papers andcoatings refer to "oven-dried" weights. Information on the binderrelates to the solid content of the binder.

The advantages of the web printing paper according to the inventionrelated to economics result, first of all, from the high share ofde-inked recycled fibers; according to an especially economicembodiment, all of the fiber used may consist of such fibers, and,secondly, from the relatively low grammage of the coating applied toboth sides. The relatively low share of binder creates a further costadvantage. Preferably, the filler share is at least 15% by weight.

Attempts by the applicant to use a qualitatively higher-valued standardLWC base paper instead of the base paper of the present invention led toa paper quality that was completely unsatisfactory in respect toprinting results. Thus, to this extent, it must be considered surprisingthat the combination according to the invention of a base papercontaining a high share of recycled fiber and a high filler share and acoating applied in relatively low grammage, in which the pigment/binderratio is also very low in comparison to the already known attempts toimprove newsprint and SC quality, permits the object of the invention tobe attained.

As already mentioned, it is preferred according to the invention thatall of the fiber used consist of recycled fibers. According to a furtherembodiment, up to 30% by weight of the base paper, relative to itsgrammage, may consist of mechanical pulp, while in the case of basepapers having a grammage of between 30 and 38 g/m², in particular, achemical pulp share of up to 20% by weight is contemplated. Mechanicalpulp and chemical pulp may also be used in mixture; however, theirmaximum share of the grammage of the base paper is <40% by weight.

In order to produce a web printing paper that meets the Europeanstandard for SC paper qualities, a base paper having a grammage of up to48 g/m² and containing, relative to its grammage, 10 to 15% by weightfiller has proved especially suitable, whereby the fiber used consistsof more than 60% by weight de-inked recycled fibers and the remainder:mechanical pulp fiber and/or chemical pulp, with all of the componentstogether equalling 100% by weight.

According to a further embodiment that is especially preferred in termsof economics, the fiber share in a base paper of this type consistsexclusively of de-inked recycled fibers.

In order to produce a web printing paper of high value in respect toquality, which corresponds in its characteristics to the usual standardLWC papers, a base paper having a grammage of at least 38 g/m²,preferably up to 58 g/m², has proved especially suitable. Such a basepaper contains 20 to 35% by weight filler, 50 to 60% by weight de-inkedrecycled fibers, remainder: mechanical pulp and/or chemical pulp,whereby all components together add up to 100% by weight. Preferably, insuch a paper, the fiber share consists exclusively of de-inked recycledfibers; however, it is possible, especially in base papers having agrammage between 38 g/m² and 45 g/m², by using up to 30% by weightmechanical pulp, as applicable, in combination with up to 20% by weightchemical pulp, to increase the strength characteristics.

In order to attain a sufficient whiteness, the recycled fibers arepreferably additionally bleached, so that according to a furtheradvantageous embodiment, a whiteness value of at least 60% results. Itis especially preferred that the whiteness value of the recycled fibersbe at least 65%, and very especially, at least 68%. The measurement ofthe whiteness value--also for the finished web printing paper--iscarried out using Filter R457 as per DIN 5033, Parts 1 to 9 and DIN 53145, Parts 1 and 2. According to a further preferred embodiment,however, the whiteness value is significantly higher, equaling up to72%. For a base paper which, after being coated, is to correspond in itswhiteness and brightness values to an SC paper, the value for whitenessis preferably 60 to 62. In a base paper which, after being coated, is tocorrespond in whiteness and/or brightness values to an LWC standardpaper, the values for whiteness and brightness are preferably 68.

To attain the highest possible filler retention, a retention aid isadded during the production of the base paper, as applicable, which isalso contained in the base paper in small quantities. In order toimprove strength, the base paper may also preferably contain cationicstarch, the addition of which is also carried out as a mass addition.

Preferably, the mineral fillers of the base paper consist primarily ofkaolin or calcium carbonate or talcum or a mixture of these substances.

In order to establish adequate strength, and especially adequate pickingresistance on the surface, according to a preferred embodiment of theinvention the binder share present in the coating is not to drop below4% by weight, relative to the pigment in the coating. Furthermore, ithas proved advantageous for the binder contained in the coating toconsist of more than 50% by weight of a film-forming latex. For webprinting papers to be printed in offset printing, polyvinyl alcohol insmall quantities, preferably between 5 and 12% by weight, relative tothe total binder content of the coating, may be present as furtherbinder components in the coating. Preferably, latices based on acrylicacid ester, polyvinyl acetate and styrene-butadiene and/or theircopolymerisates are used, as well as, especially, mixtures of these twolatex types. Other than latex and, as applicable, polyvinyl alcohol, thecoating may contain, as a further binder, starch and/or modified starch,e.g., starch ester. Especially for web printing papers to be printed inthe offset printing process, the binder of the coating may also consistprimarily of starch or, as applicable, only of starch.

The following have proved especially suitable as pigments to be used inthe coating: kaolin, calcium carbonate, talcum, titanium dioxide,aluminum hydroxide, betonite or a mixture of these pigments, wherebybentonite is used with one or more of the above-mentioned pigments in aquantity of not more than 20% by weight, relative to the total pigment.

For a web printing paper with SC qualities, which is to be printed inoffset printing, a coating in a quantity of 2 to 6/m² has provedsuitable, whereby a binder share in the coating of 10 to 15% by weight,relative to the pigment of the coating, is present and the pigmentconsists of kaolin and/or calcium carbonate or of a mixture of kaolinand talcum or of a mixture of calcium carbonate and talcum and thepigment mixture, as applicable, also contains aluminum hydroxide and/ortitanium dioxide in a quantity of not more than 20% by weight, relativeto the total pigment.

A web printing paper with the quality features of an SC paper, which isto be printed in gravure printing, preferably has a coating of 4 to 8g/m², whereby binder is present within the coating at a level of 4 to<10% by weight, relative to the pigment of the coating, and the pigmentconsists of kaolin, of calcium carbonate or of talcum or of a mixture oftalcum with kaolin or calcium carbonate.

A preferred embodiment of a web printing paper which corresponds it itslevels of quality to the known standard LWC papers and is printed inoffset printing has a coating with a grammage of 2 to 6 g/m², wherebythe quantity of the binder present in the coating is 10 to 15%, relativeto the pigment in the coating, and the pigment consist of kaolin and/orcalcium carbonate, or of a mixture of kaolin and talcum or of a mixtureof calcium carbonate and talcum, and the pigment mixture, as applicable,also contains aluminum hydroxide and/or titanium dioxide in a quantityof not more than 20% by weight, relative to the total pigment.

For a web printing paper which is to have a quality level correspondingto the known standard LWC papers but is to be used for gravure printing,the grammage of the coating is 4 to 8 g/m² and the binder is present ina quantity of 4 to <10% relative to the pigment of the coating. Aspigment, kaolin or calcium carbonate or talcum or a mixture of talcumwith kaolin or calcium carbonate is used.

In the two above-described web printing papers for gravure printing, thebinder share is preferably not more than 6% by weight, relative to thepigment in the coating.

Table 1 below shows the characteristic values of web printing papersaccording to the invention in various area-weight ranges.

                  TABLE 1                                                         ______________________________________                                        Gram-    Opacity Whiteness                                                                              Bright-      Smooth-                                mage g/m.sup.2                                                                         %       R 457    ness  Gloss 75°                                                                     ness Bekk s                            ______________________________________                                        IO  51       90      72     77    45     1,000                                    57       92      72     78    55     1,500                                IT  51       91      72     77    43     1,700                                    60       93      72     77    50     2,000                                IIO 52       88      67     72    41     1,200                                    60       90      67     72    43     1,300                                IIT 52       90      67     72    42     1,500                                    60       92      67     72    45     1,600                                ______________________________________                                    

In the above table, the following meanings apply:

I Filler share>20%

II Filler share<15%

O Offset quality

T Gravure quality

Because the waste paper from which the recycled fibers to be usedaccording to the invention are obtained contains a certain share ofcalcium carbonate and at least part of this calcium carbonate, togetherwith the recycled fibers and other possible mineral fillers, is added tothe mass from which the base paper is produced, a low-acid or neutralmethod has proved advantageous, in order to prevent, as far as possible,gypsum formation, which will occur due to the interaction of aluminumsulfate and calcium carbonate under acidic conditions. The use of themineral pigments contained in the water paper material, whichessentially consist, along with calcium carbonate, of kaolin, is by nomeans undesirable, however; rather, according to the invention an effortis made to reintroduce the highest possible share of these pigments intothe paper production process together with the recycled fibers. It hasproved advantageous to omit any washing process while recovering therecycled fibers when a higher share of the fillers contained in thewaste paper are to be recycled. However, if the waste paper to be usedcontains a high filler share and, in addition, if an even higher shareof recycled fibers are to be used, and if only moderate filler contentis called for in the base paper to be produced, then a certain degree ofwashing may be desired, especially with a filler share of <15% byweight.

The relatively high share of filler, especially filler contents of morethan 15% by weight, may lead to an uneven filler distribution across thecross-section of the base paper. Preferably, therefore, a so-calledtwin-former is used to produce the base paper, with which thedehydration of the formed paper web is carried out simultaneously onboth sides between two wires.

If, according to a particularly preferred embodiment of the processaccording to the invention, the coating of the base paper is carried outby means of a film press, a web printing paper of satisfactory gloss,good smoothness and sufficient picking resistance is created, despitethe low grammage of the coating compared to LWC papers, although arelatively lower binder/pigment ratio exists. It is already known thatthere is an interaction between the high filler share of the base paper,the indirect application of the coating and its composition, with theresult that during the coating process the still-fluid coating masspenetrates into the base paper only so far that a good connectionresults between the base paper and coating, while the majority of thecoating mass is available for formation of the coating paper surface.

The coating can also be applied in two worksteps in such a manner thatfirst a pre-coat and then a top coat is applied; however, theapplication of the coating in a single workstep is preferred.

In order to form a sufficiently smooth and glossy coating, the webprinting paper is, after the application and drying of the coating,treated on a standard super-calendar or hot-soft calendar.

According to a further preferred embodiment of the invention, productionis carried out on-line, i.e., the base paper, after it dries, is feddirectly to the coater for application of the coating and, asapplicable, satinized directly following the application and drying ofthe coating, without intermediate winding.

The following examples serve to explain the invention in greater detail:

EXAMPLE 1

On a long-sieve paper machine, with a grammage of 45 g/m², a base paperconsisting of:

62% by weight de-inked recycled fibers

24% by weight wood pulp (TMP)

14% by weight filler

is produced.

Whiteness of recycled fibers: 61%

Grinding degree of mechanical pulp: 70 degrees SR

Filler components:

65% by weight kaolin

35% by weight calcium carbonate

10% by weight talcum

With a coater known in the literature as a "speed-sizer," a coating isapplied to the dried base paper web having a grammage of 5.5 g/m² eachside and satinized after drying on a super-calendar. The pigmentcomposition of the applied pigment consists of:

70% by weight kaolin

30% by weight talcum

and has a binder share of 5% by weight, relative to the total pigmentshare, consisting of butadiene styrene latex. In a lesser quantity, thecoating mass used for producing the coating also contains additives forimproved rheology.

The result is a web printing paper to be printed using the gravureprocess, which has the characteristics indicated in Table 2.

EXAMPLE 2

Under the same conditions as those described in Example 1, a base paperis produced that has the following composition:

62% by weight de-inked and bleached recycled fibers having a whitenessvalue of 66%

28% by weight filler

10% by weight mechanical pulp

Filler composition and grinding degree of the mechanical pulp correspondto Example 1. The base paper has a grammage of 49 g/m² and is coatedwith the coating described in Example 1, but with a grammage of 5.5 g/m²each side.

The result is a web printing paper to be printed using the gravureprocess, which has the characteristics indicated in Table 2.

EXAMPLES 3 AND 4

In order to produce web printing papers to be printed in offsetprinting, base papers having the composition indicated in Examples 1 and2 are provided with a coating, the pigment share of which consists of30% by weight kaolin and 70% by weight calcium carbonate; the coatingcontains 13% by weight binder, consisting of 11% by weight of abutadiene styrol latex and 2% by weight starch as well as an opticallightener added in the usual amount. After the coating dries, the papersare treated on a super-calendar. The base paper used in Example 3corresponds to that described in Example 1; in Example 4, the base paperdescribed in Example 2 was used, but with a grammage of 49 g/m².According to Example 3, 4.5 g/m² each side were applied; according toExample 4, 4 g/m² each side. The characteristics of the produced papersare also found in Table 2.

                  TABLE 2                                                         ______________________________________                                                  Smoothness                                                                              Gloss                                                     Example   Bekk s    75°                                                                             Whiteness                                                                            Opacity                                   ______________________________________                                        1         1,100     40       66     96                                        2         1,300     51       72     94                                        3         1,000     38       64     95                                        4         1,100     53       72     93                                        ______________________________________                                    

What is claimed is:
 1. A web printing paper, comprising a base papercontaining mineral filler, recycled fibers, and one of mechanical pulpand chemical pulp, and having a coating on both sides of said basepaper, said coating containing a binder and a pigment, said pigmentconsisting of kaolin, calcium carbonate, talcum, titanium dioxide,aluminum hydroxide or mixtures thereof, said base paper having agrammage of 30 to less than 60 g/m², and relative to its grammage,contains greater than 50% by weight de-inked recycled fibers, 10 to 35%by weight mineral filler, the remainder being one of mechanical pulp andchemical pulp, all weight pans adding up to 100% by weight; and thecosting per side having a grammage of 2 to 8 g/m² and the binder,relative to pigment of coating, being present in a quantity of not morethan 15% by weight.
 2. The web printing paper of claim 1, wherein themineral filler is present in an amount of at least 15% by weight.
 3. Theweb printing paper of claim 1, wherein the base paper relative to itsgrammage contains one of up to 30% by weight mechanical pulp and up to20% by weight chemical pulp.
 4. The web printing paper of claim 1,wherein the base paper, relative to its grammage, contains more than 60%by weight de-inked recycled fibers, 10 to 15% by weight mineral filler,the remainder being one of mechanical pulp and chemical pulp, all weightparts adding up to 100% by weight and the base paper has a grammage ofup to 48 g/m².
 5. The web printing paper as in claim 1, wherein the basepaper, relative to its grammage, comprises:20 to 35% by weight filler,less than 50 to 60% by weight de-inked recycled fibers and one of up to30% by weight mechanical pulp, and up to 20% by weight chemical pulp allweight parts adding up to 100% by weight and the base paper has agrammage of at least 38 g/m².
 6. The web printing paper of claim 1,wherein the recycled fibers are bleached.
 7. The web printing paper ofclaim 1, wherein the recycled fibers have a whiteness of at least 60%.8. The web printing paper of claim 1, wherein the base paperadditionally contains a retention aid for the filler.
 9. The webprinting paper of claim 1, wherein the base paper additionally containscationic starch.
 10. The web printing paper of claim 1, wherein themineral filler of the base paper comprises kaolin, calcium carbonate,talcum or a mixture thereof.
 11. The web printing paper of claim 1,wherein the binder contained in the coating equals not less that 4% byweight, relative to the pigment of the coating.
 12. The web printingpaper of claim 1, wherein the binder contained in the coating comprisesmore than 50% by weight of a film-forming latex.
 13. The web printingpaper of claim 1, wherein the coating contains, as binder, polyvinylalcohol in a quantity of 5 to 15% by weight, relative to the totalbinder content of the coating.
 14. The web printing paper of claim 1,wherein:the coating per side has a grammage of 2 to 6 g/m², the binderis present in the coating in a quantity of 10 to 15% by weight relativeto the pigment of the coating, the pigment consists of one of kaolin andcalcium carbonate, or a mixture of kaolin and talcum or a mixture ofcalcium carbonate and talcum, and in the pigment mixture, optionally,one of aluminum hydroxide and titanium dioxide is present in an amountof not more that 20% by weight, relative to the total pigment.
 15. Theweb printing paper of claim 1, wherein:the coating per side has agrammage of 4 to 8 g/m², the binder is present in the coating in anamount of 4 to less than 10% by weight relative to the pigment of thecoating, the pigment consists of one of kaolin and calcium carbonate; ora mixture of kaolin and talcum, or of a mixture of calcium carbonate andtalcum; and in the pigment mixture, optionally, one of aluminumhydroxide and titanium dioxide is present in an amount of not more than20% by weight, relative to the total pigment.
 16. The web printing paperof claim 1, wherein:the coating per side has a grammage of 2 to 6 g/m²,the binder is present in the coating is a quantity of 10 to 15% byweight, relative to the pigment in the coating, the pigment consists ofone of kaolin and calcium carbonate; or of a mixture of kaolin andtalcum, or of a mixture of calcium carbonate and talcum; and in thepigment mixture, optionally, one of aluminum hydroxide and titaniumdioxide is present in a quantity of not more than 20% by weight,relative to the total pigment.
 17. The web printing paper of claim 1,wherein:the coating per side has a grammage of 4 to 8 g/m², the binderis present in the coating in an amount of 4 to less than 10%, relativeto the pigment of the coating, the pigment consists of one of kaolin andtalcum; or of calcium carbonate or of calcium carbonate and talcum. 18.A web printing paper, comprising a base paper containing mineral fillerand recycled fibers and on both sides of said base paper, said coatingcontaining a binder and a pigment, said pigment consisting of kaolin,calcium carbonate, talcum, titanium dioxide, aluminum hydroxide ormixtures thereof;said base paper having a grammage of 30 to less than 60g/m² and containing, relative to its grammage, 10 to 35% by weightmineral filler; the remainder being de-inked recycled fibers, all weightparts adding up to 100% by weight; and the coating per side having agrammage of 2 to 8 g/m² and the binder, relative to pigment in thecoating, being present in a quantity of not more than 15% by weight. 19.The web printing paper of claim 18, wherein the base paper relative toits grammage contains 10 to 15% by weight mineral filler, the remainderbeing de-inked recycled fibers, and the base paper has a grammage up to48 g/m².
 20. The web printing paper of claim 18, wherein the base paper,relative to its grammage, comprises:20 to 35% by weight filler, theremainder being de-inked recycled fibers, and the base paper has agrammage of at least 38 g/m².
 21. The web printing paper of claim 20,wherein the base paper has a grammage of up to 58 g/m².
 22. The webprinting paper of claim 18, wherein the mineral filler is present in anamount of at least 15% by weight.
 23. The web printing paper of claim22, wherein the base paper relative to its grammage contains one of upto 30% by weight mechanical pulp and up to 20% by weight chemical pulp.24. The web printing paper of claim 18, wherein the recycled fibers arebleached.
 25. The web printing paper of claim 18, wherein the recycledfibers have a whiteness of at least 60%.
 26. The web printing paper ofclaim 18, wherein the base paper additionally contains a retention aidfor the filler.
 27. The web printing paper of claim 18, wherein the basepaper additionally contains cationic starch.
 28. The web printing paperof claim 18, wherein the mineral filler of the base paper compriseskaolin, calcium carbonate, talcum or a mixture thereof.
 29. The webprinting paper of claim 18, wherein the binder contained in the coatingequals not less that 4% by weight, relative to the pigment of thecoating.
 30. The web printing paper of claim 18, wherein the bindercontained in the coating comprises more than 50% by weight of afilm-forming latex.
 31. The web printing paper of claim 18, wherein thecoating contains, as binder, polyvinyl alcohol in a quantity of 5 to 15%by weight, relative to the total binder content of the coating.
 32. Theweb printing paper of claim 18, wherein:the coating per side has agrammage of 2 to 6 g/m², the binder is present in the coating in aquantity of 10 to 15% by weight relative to the pigment of the coating,the pigment consists of one of kaolin and calcium carbonate, or amixture of kaolin and talcum or a mixture of calcium carbonate andtalcum and in the pigment mixture, optionally, one of aluminum hydroxideand titanium dioxide is present in an amount of not more that 20% byweight, relative to the total pigment.
 33. The web printing paper ofclaim 18, wherein;the coating per side has a grammage of 4 to 8 g/m²,the binder is present in the coating in an amount of 4 to less than 10%by weight relative to the pigment of the coating, the pigment consistsof one of kaolin and calcium carbonate; or a mixture of kaolin andtalcum, or of a mixture of calcium carbonate and talcum; and in thepigment mixture, optionally, one of aluminum hydroxide and titaniumdioxide is present in an amount of not more than 20% by weight, relativeto the total pigment.
 34. The web printing paper of claim 18,wherein:the coating per side has a grammage of 2 to 6 g/m², the binderis present in the coating is a quantity of 10 to 15% by weight, relativeto the pigment in the coating, the pigment consists of one of kaolin andcalcium carbonate; or of a mixture of kaolin and talcum, or of a mixtureof calcium carbonate and talcum, and in the pigment mixture, optionally,one of aluminum hydroxide and titanium dioxide is present in a quantityof not more than 20% by weight, relative to the total pigment.
 35. Theweb printing paper of claim 18, wherein:the coating per side has agrammage of 4 to 8 g/m², the binder is present in the coating in anamount of 4 to less than 10%, relative to the pigment of the coating,the pigment consists of one of kaolin and talcum; or of calciumcarbonate or of calcium carbonate and talcum.
 36. A process forproducing a web printing paper, comprising a base paper containingmineral filler, recycled fibers, and one of mechanical pulp and chemicalpulp, and having a coating on both sides of said base paper, saidcoating containing a binder and a pigment, said pigment consisting ofkaolin, calcium carbonate, talcum, titanium dioxide, aluminum hydroxide,or mixtures thereof; said base paper having a grammage of 30 to lessthan 60 g/m², and relative to its grammage, contains greater than 50% byweight de-inked recycled fibers, 10 to 35% by weight mineral filler, theremainder being one of mechanical pulp and chemical pulp, all weightparts adding up to 100% by weight; and the coating per side having agrammage of 2 to 8 g/m² and the binder, relative to pigment of coating,being present in a quantity of not more than 15% by weight wherein theproduction of the base paper is carried out at a pH value of between 6.5and 8.5.
 37. The process of claim 36, wherein the recycled fibersoriginate from waste paper material and wherein the waste paper materialis dissolved and the dissolved waste paper material and the recycledfibers are not washed for retaining the highest possible share of themineral pigment.
 38. The process of claim 36, wherein the base paper isdewatered and the dewatering is carried out simultaneously on both sidesbetween two wires of a paper machine.
 39. The process of claim 36,wherein the coating is applied by means of a film press.
 40. The processof claim 36, wherein the coating comprises a pre-coat and a top coat.41. The process of claim 36, comprising the steps of coating the paperand drying the coating; and wherein the web printing paper is treated,after the coating is dried on a super-calendar or a hot-soft calendar.